Anyone who has struggled with an arcade claw machine knows that controlling a mechanical arm is not as easy as it looks.
Excavator operators face a much harder version of the same problem. They must coordinate several joystick movements to control the machine’s boom, arm, bucket and cab at the same time.
Learning those controls can take months or even years.
Now, engineers at MIT have developed a more natural control system that could dramatically shorten that learning curve.
Instead of traditional joysticks, the new system uses a small mechanical arm that resembles an excavator’s own arm and bucket. An operator holds the device and moves it with their arm and hand. A virtual excavator then copies those movements on an immersive six-screen display.
The researchers call their system the World-Space Interface, or WSI. The idea is to remove much of the mental translation required with conventional controls.
With joysticks, an operator has to remember which movement of each control produces a particular movement of the excavator. With the new system, the person can simply move the miniature arm in the direction they want the real machine to move.
MIT researchers developed the technology with collaborators from Sumitomo Heavy Industries in Japan. The project began after researchers considered the challenge of replacing Japan’s aging population of experienced heavy machinery operators.
To test the system, the team created 15 virtual excavation environments, including construction sites, highways, forests, riverbanks, mines and urban areas. Volunteers performed realistic jobs such as scooping and dumping material, digging trenches, grading soil, clearing roads and breaking up rocks.
Both experienced operators and beginners trained for one hour a day over seven days. Some used a traditional joystick simulator, while others used the new arm-based controller.
The difference was striking. Beginners using joysticks initially performed worse than experienced operators, although they gradually improved with practice. But when volunteers used the World-Space Interface, beginners performed about as well as experts from the beginning.
The researchers believe the technology could eventually do more than improve training. A similar controller could be installed inside an excavator, allowing operators to control the machine using natural arm movements instead of joysticks.
It could also make remote operation easier. For dangerous construction, mining or disaster sites, an operator could remain safely away from the area while controlling an excavator remotely.
The MIT team is now developing another important feature: touch feedback, known as haptics. For example, when an excavator picks up a heavy load of rocks, the miniature arm could create resistance that allows the operator to feel the weight.
Major manufacturers are already developing virtual excavator simulators, but most still rely on conventional joysticks. The MIT researchers believe their approach could make operating heavy machinery much easier to learn.
If the technology translates successfully from simulation to real machines, future excavator operators may be able to start performing useful tasks far sooner—potentially turning years of learning into a much shorter training process.
